Beefy Boxes and Bandwidth Generously Provided by pair Networks
Clear questions and runnable code
get the best and fastest answer
 
PerlMonks  

Re^2: One true regexp for untainting windows filenames?

by jaldhar (Vicar)
on Jan 08, 2009 at 23:42 UTC ( #735047=note: print w/ replies, xml ) Need Help??


in reply to Re: One true regexp for untainting windows filenames?
in thread One true regexp for untainting windows filenames?

Thanks for the tip. I found slightly more understandable code in File::Spec which has resulted in the following regexps: for Unix...

qr{(\A (?: .* / (?: \.\.?\z )? )? [^/]* )}msx;
...and Windows (includes UNC paths)...
qr{(\A (?: [a-zA-Z]: | (?:\\\\\\\\|//)[^\\\\/]+[\\\\/][^\\\\/]+ )? (?:.*[\\/](?:\.\.?\Z(?!\n))?)? .* )}msx;

--
જલધર


Comment on Re^2: One true regexp for untainting windows filenames?
Select or Download Code
Re^3: One true regexp for untainting windows filenames?
by ikegami (Pope) on Jan 09, 2009 at 05:33 UTC

    There is no a string that

    qr{(\A (?: .* / (?: \.\.?\z )? )? [^/]* )}msx

    won't match.

    It's wrong for two reasons.

    • "foo" gets "untainted" as "".
    • "x/xx\0xx"" is believed to be a valid file name, but it isn't.

    Valid unix paths and only valid unix paths match

    qr{^([\0]+)\z}

    (Although that doesn't mean there can ever be a file referenced by that path.)

Log In?
Username:
Password:

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://735047]
help
Chatterbox?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others musing on the Monastery: (5)
As of 2015-07-04 18:23 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    The top three priorities of my open tasks are (in descending order of likelihood to be worked on) ...









    Results (60 votes), past polls